A variety of multi-monosaccharides such as glycoproteins, glycolipids, glycosaminoglycans, and polysaccharides are composed of varying amounts of different monosaccharide units chemically linked together as constituent building blocks. The knowledge of their composition (e.g., the identity of the constituent monosaccharide building blocks coupled with their frequency of occurrence) appeared to provide a roadmap to break the chemical links between the constituent monosaccharide units to harvest them—hopefully in yields near the frequency of their occurrence. By using such a “Decoupling Approach,” one might recover sought after monosaccharides in sufficient yields at a low cost, and at high production throughput levels with less complexity, for various uses.
Monosaccharides are carbohydrates that cannot by hydrolyzed into simpler carbohydrates. Of all the monosaccharides, glucose is the most important due to its use as the major metabolic fuel of mammals and as an energy source for plants. There are also eight commonly recognized essential monosaccharides: mannose, xylose, galactose, fucose, arabinose, N-acetylneuraminic acid, N-acetylgalactosamine, and N-acetylglucosamine. Of these monosaccharides, only glucose and galactose are found in a typical diet.
Because of the importance of saccharides in biological systems, methods for the synthesis of monosaccharides are of considerable utility. Monosaccharide units are essential for practical synthesis of all glycoproteins, glycolipids, glycosaminoglycans, and polysaccharides. However, monosaccharide synthesis is typically performed using classical organic synthesis methodologies, many of which are labor intensive and require multiple steps, or via enzymatic breakdown of polysaccharides.
N-acetylglucosamine is a valuable pharmacological agent in the treatment of a wide variety of ailments. N-acetylglucosamine does not have any established negative side effects. Since N-acetylglucosamine is a valuable and important component of protein synthesis in the animal body, it has a positive effect on tissue regeneration. N-acetylglucosamine also has therapeutic potential in the prevention and/or treatment of a wide variety of diseases such as gastritis, food allergies, inflammatory bowel disease (IBD), diverticulitis, acute and chronic forms of rheumatoid arthritis and osteoarthritis, as well as the pathological conditions arising from metabolic disorders of the osteoarticular tissues.
N-acetylglucosamine is not widely available in the marketplace. It is currently produced by the acetylation of glucosamine using an organic acetylating reagent such as acetic anhydride, an expensive and difficult step. These processes suffer from poor product yields (in the range of 50% conversion of substrate to glucosamine). Another currently available process to synthesize N-acetylglucosamine includes fermentation and isolation from several products.
Decoupling Approach as Hypothetical
Though the past tense is used herein, it is to be understood that the “Decoupling Approach” described herein is a hypothetical depiction provided to illustrate and analyze certain difficulties and problems that may be encountered with such approach. Having provided such qualification, it is to be understood that this illustration recites hypothetical multi-monosaccharide compounds with hypothetical monosaccharide labels in varying hypothetical amounts of the same, as set forth in connection with hypothetical recovery values presented together with a generic decoupling procedure to provide a better understanding of certain problems and difficulties that may be encountered with such approach.
Additionally, the qualifier “Without being bound by theory” is applicable to statements in this application where there is any particular causal link discussed or put forth as to cause and effect, as to cause and result, or as to any theory of causation or theory of operation described or addressed herein in any fashion. Such qualifier is made as to each such statement, whether made expressly or by implication in view of this paragraph and its applicability to this entire application, wherever appropriate.
Having made the foregoing qualifications, it was expected that when the strategy of decoupling constituent monosaccharide units by breaking the chemical links between them would be tried, certain sought monosaccharides (and sought monosaccharide combinations) in desired yields could be successfully acquired at low cost, and at high production throughput levels with low complexity. Unfortunately, such expectations remained unfulfilled for quite some time as these types of problems are further described below. Without being bound by theory, it is believed that the sought constituent monosaccharides (and sought monosaccharide combinations) may not have been recovered in the expected yields, in part, because during the decoupling process, the original constituent monosaccharide chemical structures were not sufficiently conserved/preserved.
Without being bound by theory, it is believed that the sought monosaccharides (and sought combinations thereof) were not acquired as expected or desired because some monosaccharides (and monosaccharide combinations) were converted into unwanted compounds or into other unwanted monosaccharides so that the sought-after monosaccharides in the desired yields could not be easily recovered. Accordingly, this approach was deemed too cumbersome to execute due to such problems and difficulties.
Further, small scale bench processing is typically deemed too inefficient when scaled up to satisfy high throughput levels at a low cost with less complexity.
Illustration of Decoupling Approach With More Specific Hypothetical Labels and Values
Consider, for example, a particular multi-monosaccharide (←continued—A-B-C-D—continued→) containing monosaccharides hypothetically labeled as A, B, C and D to convey that they are not identical monosaccharides. Accordingly, it is to be understood that the monosaccharides so labeled with different letters are monosaccharides of different chemical structures represented by the notation: A≠B≠C≠D. With that understanding, now consider that a generic procedure is implemented to decouple and to recover the constituent monosaccharides A, B, C, and D originally present in the multi-monosaccharide of the structure (←continued—A-B-C-D—continued→). The plan is to recover the original amounts of A, B, C, and D present in the starting multi-monosaccharide structure (←continued—A-B-C-D—continued→) using the decoupling procedure implemented, as to each of A, B, C, and D originally present.
In this context, consider a breakdown hydrolysis process to decouple the links between A, B, C, and/or D while preserving or substantially preserving the original (or nearly original) content levels of A, B, C, and D originally present in (←continued—A-B-C-D—continued→) at post breakdown and subsequent recovery of the constituent A, B, C, and D monosaccharide units.
Now further consider that the monosaccharide B is of particular interest because hypothetically it is considered difficult to obtain in desired sufficient yields, at low cost, at high throughput production levels and with low complexity, etc.
In such hypothetical illustration herein below, consider the aforementioned multi -monosaccharide compound (←continued—A-B-C-D—continued→) originally containing:                20% monosaccharide units A;        40% monosaccharide units B;        20% monosaccharide units C; and        20% monosaccharide units D.        (TOTAL=100% before attempted breakdown of constituent monosaccharides.).However, pursuant to this hypothetical, after being subjected to decoupling and upon breakdown, the yields of the constituent monosaccharides (A, B, C and D) originally present in (←continued—A-B-C-D—continued→) were quite disappointing with respect to recovery of monosaccharide B of interest:        40% monosaccharide units A;        0% monosaccharide B;        49% monosaccharide units C; and        11% monosaccharide units D.        (TOTAL=100% after breakdown of recovered monosaccharides.).        
In effect, during the above-noted decoupling and implemented breakdown seeking constituent monosaccharides, none of monosaccharide B was recovered. In other words, even though the relative percent values—before breakdown (40% B)—and—recovery after breakdown (0% B)—are hypothetical values, one would be quite surprised were the hypothetical presented herein a true enough qualitative reflection of reality where the breakdown process were to yield no B when starting out with 40% B. While it could be that much of the monosaccharide B simply could not be recovered, it is quite possible that monosaccharide B was converted into another monosaccharide or into some other undesirable or undetectable chemical entity.
The problem being, of course, that no B was recovered from an original content starting out at 40% B. In this hypothetically illustrative situation where the breakdown process yielded no monosaccharide B from a multi-monosaccharide compound originally containing 40% monosaccharide B (and hypothetically consider such result were qualitatively applicable to one or more of each sought monosaccharide that is difficult to obtain at low cost, and at high throughput levels with low complexity), the difficulty encountered with this “Decoupling Approach” to recover monosaccharide B of particular interest is readily apparent. Now, noting that the foregoing may not apply exactly to every situation, it still would apply to those instances where these types of difficulties have not been resolved to satisfy the need to obtain a hard-to-obtain monosaccharide (or hard to obtain at a reasonable price and at high throughput levels). The same may apply to a combination of hard to obtain monosaccharides as well.
Alternate Synthesis Approach with Hypothetical Labels
In view of resolving the difficulties noted one might alternatively attempt to synthesize the desired monosaccharide B in sufficient yield by relying on a classical organic synthetic route for each difficult-to-obtain monosaccharide represented by the generic label B. In that context, one could attempt to synthesize the monosaccharide B of interest in sufficient yield. However, such classical synthetic organic methods for making the monosaccharide B of interest (with sufficient yield) can often be likewise difficult to accomplish—depending on the particular relevant structure involved.
When taking the structure of interest into consideration, one not only has to consider chemical identity but may also have to take into account (1) various polymorphic forms (if any), (2) varying reactivities (if any), (3) varying solubilities (if any), (4) varying difficulties of each variant form, (5) varying stabilities, and (6) potentially other known but unpredictable variations, (7) inconsistent reactivities, etc. and (8) any unknown variables that may be found only after failed attempts to synthesize a monosaccharide B of particular interest, and so on. Each of the foregoing factors (1)-(8) emphasize the complexity involved with such a classical synthetic approach given that one may need to synthesize compounds hard-to-synthesize from “scratch”.
And, the solution to the problem of synthesizing the particularly difficult-to-make monosaccharide may be so difficult to solve that the solution is not even remotely within reach. In such case, a particular compound may be very expensive or nearly impossible to obtain in quantities sought at low cost, etc.
Such levels of uncertainty increase the complexity of this hypothetical classical synthetic approach. In fact, in every (or nearly every) instance where a reliable and reproducible synthetic route is unknown, the complexity escalates in part due to the uncertainty of meeting a high throughput level if needed (say, for example, immediately in response to some emergency), irrespective of cost and complexity. To appreciate the difficulties, one has to simply multiply the number of such potentially problematic considerations (i.e., see (1)-(8) listed two paragraphs above or more as some may yet remain to be identified) by the number of monosaccharides being sought. By doing so, the magnitude of the complexity skyrockets to the point of foregoing this alternate approach as well.
But, even if a classical synthetic organic method for the synthesis of monosaccharide B of interest were known, the cost, yield, efficiency, time, and the like may still not be sufficiently favorable to make the desired monosaccharide B of interest at sufficiently low cost, in desirable yield and with the level of efficiency necessary to meet high throughput levels, especially if an order were placed with little notice. Other considerations as to purity, separation, isolation, and/or recovery may still need to be solved, if such exist. Thus, such methods may still suffer from a variety of disadvantages, difficulties and/or problems, including: unsuitable and/or undesirable time requirements, cost and/or resource intensive procedures, coupled with insufficient yields, and/or too much complexity, and too high throughput demands that could not be readily or otherwise met.
Also, the above-noted problems that may be encountered with respect to monosaccharide B of interest can be analogized to a variety of monosaccharide(s) that are difficult-to-synthesize or recover by a decoupling process in adequate yield at low cost. Thus, it may be necessary to find another way to overcome the problems encountered with respect to the formation of the hard-to-make or hard-to-obtain monosaccharide B of interest in sufficient yield as sought, preferably in a cost effective and time efficient manner.
In view of the above, another approach may be better suited to overcome one or more of the foregoing difficulties. Thus there is a need for a yield efficient and cost efficient monosaccharide production system to prepare compositions including nutritional compositions having at least one saccharide and other beneficial nutritional components derived from cheap and readily obtainable starting materials. To that end, the present inventors approached the problem(s) from a quite different view in order to prepare nutritional compositions comprising one or more saccharides.